Protective helmet



FIG. 1 is a perspective view of a protective helmet showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof;

FIG. 7 is a bottom view thereof, the details shown in broken lines form no part of the claimed design; and,

FIG. 8 is a perspective view thereof in a folded configuration. 

CLAIM We claim the ornamental design for a protective helmet, as shown and described. 